The DVC might be the cheapest replacement, but may not be the best. I know several people who have built the F20 with the RSS390HF-4 and are very satisfied. Without side by side real world measurements, it is really hard to say which is "better". On paper? You decide.

Power handling: 500 watts RMS (800 watts max)

Impedance: 4 ohms

Frequency range: 18 - 800 Hz • Fs: 18 Hz

Magnet weight: 150 oz.

SPL: 90 dB 2.83 V/1m, 87 dB 1W/1m

Xmax: 14mm

Power handling: 350 watts RMS/per coil (600 watts total)

Impedance: 8 ohm per coil / 4 ohm total

Frequency range: 20-450 Hz

Magnet weight: 112 oz

Frequency range: 19 Hz • SPL: 90 dB 1W/1m

Xmax: 15.1mm

**Dayton Audio RSS390HF-4 Reference HF @ $172.69**Power handling: 500 watts RMS (800 watts max)

Impedance: 4 ohms

Frequency range: 18 - 800 Hz • Fs: 18 Hz

Magnet weight: 150 oz.

SPL: 90 dB 2.83 V/1m, 87 dB 1W/1m

Xmax: 14mm

**Dayton Audio DVC385-88 DVC @ $139.85**Power handling: 350 watts RMS/per coil (600 watts total)

Impedance: 8 ohm per coil / 4 ohm total

Frequency range: 20-450 Hz

Magnet weight: 112 oz

Frequency range: 19 Hz • SPL: 90 dB 1W/1m

Xmax: 15.1mm